Composite structures that include a core sandwiched between face sheets are used for many purposes. Often the core includes cells or air pockets to reduce the weight of the composite structure as compared to a similar structure made from solid materials (i.e., materials without cells or air pockets). The reduced weight of these composite structures has led the aircraft industry to use such composite structures to reduce the weight of aircraft components.
In sandwich structures the core can serve several purposes, such as providing stiffness to the structure, insulating the structure, providing thickness to the structure to achieve desired dimensional characteristics, to offset the face sheets, to support and stabilize the face sheets, etc. However, there can be trade-offs with using sandwich composite structures rather than solid materials. For example, sandwich composite structures can have reduced material performance characteristics. Additionally, such sandwich composite structures may have less than optimal resistance to damage by impact with foreign objects. Hence, when aircraft components are made using sandwich composite structures, the components may require relatively frequent inspection and replacement. Accordingly, there is a need for improved cores that provide greater impact resistance, which may enable a greater range of uses of the sandwich composite structures.